RESEARCH PROPOSAL: Scientific Merit: The aim of this work is to establish the function of the mouse homologue of CMF-1, a novel protein characterized by the Bader laboratory as possibly playing a role in chick cardiogenesis. The cloning of the mouse homologue will be aimed at eventually knocking it out and establishing the phenotype, both in vitro and in vivo. While the scientific merit of the project as it stands now is good, the preliminary data are so scarce that a knockout approach fails to engender an outstanding level of enthusiasm. Before contemplating a knockout, a specific probe should have rapidly been generated and used for both whole mount and section-oriented in situ's. Until these data are generated, the rationale for undertaking a three year experimental plan is simply too weak.